Abrasive blast cleaning machine



March 13, 1934. P. H. BEST ABNAsIvE BLAST CLEANING MACHINE 4Sheets-Sheet l Filed March 23, 1932 .IIIII ,IMPI I- Mh am wm Mai-ch 13,1934. P. H. BEST f 1,951,008

ABRASIVE BLAST CLEANING MACHINE Filed March 25, 1952 4 Sheets-Sheet 2 4Sheets-Sheet 3 0 w @M m l I. 9 0J 8%: 9 .7V 6 F. a s .m L 9 \\f 6. J fw, IM w 11 Q March 13, 1934. P. H. BEST ABRASIVE BLAST CLEANING MACHINEFiled March 2:5, 1932 March 13, 1934.

P. H. BEST ABRASIVE BLAST CLEANING MACHINE Filed March 23, 1952 4Sheets-Sheet 4 Patented Mar. 13, 193,4

PATENT OFFICE ABRASIVE BLAST CLEANING MACHINE Percival H. Best,Bridgeport, Conn., assigner to The Acme Shear Company, Bridgeport,Conn., a corporation of Connecticut Application March 23, 1932, SerialNo. 600,646

17 Claims.

This invention relates to new and useful improvements in sand blastapparatus and has particular relation to a sand blasting machine forcleaning castings.

An object of the invention is to provide a sand blasting machineincluding a cabinet, a conveyor for carrying articles to be cleaned intoand out of the cabinet, and means directing a sand blast against thearticles while they are 1n the cabinet in such a way as tosimultaneously clean both sides of the castings.

It is also an object of the invention to provide a construction and anarrangement whereby the castings are carried through the sand blast withone side directed toward the blast, and are then turned through a halfrevolution and carried back through the blast with the other side turnedtoward it.

A further object is to provide a machine in which comparatively fragilearticles can be cleaned with practically no breakage.

Another object is to provide a machine as stated and which is easy tooperate it being only necessary for the operator to place the articlesto be cleaned on and remove them from a conveyor, and which is of simpleconstruction whereby it may be economically built and operated at a lowcost.

A further object is to provide a machine as stated and which is soconstructed that workmen employed about the machine will not be troubledwith dust from the machine and which includes means whereby the usedsand is cleaned and recovered for further use.

Other objects and advantages will become apparent from a considerationof the following detailed description taken in connection with theaccompanying drawings wherein an embodiment of the invention is shown.It will, of course, be understood that the drawings and description arefor the purpose of making clear the principles of the invention and thatthe invention is not limited to the details disclosed but includes allsuch variations and modifications as fall within the spirit of theinvention and the scope of the appended claims.

In the drawings:

Fig. l is a front elevational View of a completetion openings 32 closedas by heavy glass or the Fig. 5 is an edge view of the supporting meansor hook;

Fig. 6 is an elevational detail view on an enlarged scale showing aportion of a supporting frame;

Fig. 7 is a front elevational View on an enlarged scale showing theconnection between the conveyor and a supporting hook;

Fig. 8 is a sectional view taken substantially along the une e-s of Fig.7; 65

Fig. 9 is an elevational view on an enlarged scale showing a portion ofthe conveyor means;

Fig. 10 is a sectional view on an enlarged scale, the View being takensubstantially on the line 10-10 of Fig. 3; 70

Fig. 1l is a front elevational view on an enlarged-scale and showing aportion of the trolley or supporting means for the conveyor;

Fig. 12 is aplan view of a link means connecting parts of the trolleymeans of Fig. 11; 75

Fig. 13 is a detail view showing said link means as the portion of theconveyor to which it is attached passes about a sprocket wheel; and

Fig. 14 is an elevational view showing a sand cleaning and recoveringmeans. 80

Referring in detail to the drawing, the improved sand blasting machineas herein disclosed includes a cabinet 15 supported as by legs oruprights 16 and comprising front and rear walls 17 and 18, end walls 19and 20, a top wall 21 and an inclined bottom wall 22 open at its lowerend as at 23 (see Fig. 2). The entire cabinet may be constructed of arelatively heavy gauge sheet metal the parts being riveted, welded orotherwise secured together as desired. The top wall of the cabinet isprovided with a somewhat U-shaped slot the arms of which are designated24 and 25, the said arms opening through the end 19 of the cabinet andthe said arms at their inner ends being connected whereby a means (to bedescribed) may enter one arm of the slot and travel through the slotleaving it by the other arm. l

Within the cabinet opposite the front wall 17 thereof there is mounted astop or baffle plate 26 of steel or the like said-plate being secured atits bottom edge as to the angle member 27 and at its upper edge beingmounted between the angle members 28 as fully shown in Fig. 2. To thefront side of this plate there is secured a sheet of rubber 29 thepurpose of which will later more fully appear. A pair of openings 30 areshown in the wall 17 and these openings are adapted to accommodate sandblast nozzles 3l as shown. This side of the cabinet may also be providedwith observalike to prevent the escape of dust into the atmosphere aboutthe machine. Of course, the nozzles 31 are connected with suitableapparatus whereby air under pressure and sand are supplied to thenozzles which are adapted to direct a sand blast suggested at 33 towardthe rubber pad or sheet 29 and the invention includes means for carryingarticles to be cleaned through said sand blast and then out of thecabinet. This means includes suitable frame members 34, 35, 36, 37 and38 which while all of the same or substantially the same constructionare given separate designating characters for the purpose of clarifyingthe description. The frame members each include a pair of outer uprightportions or legs 39 and 40 connected at their upper ends as by a crosspiece 41 from which depends a pair of spaced bars or members 42connected at their lower 'ends as by a cross piece 43. By reference toFigs. 1, 2 and 6 it will be noted that the outer legs 39 and 40 of theframe members 34, 35, 36 andl 37 are provided with foot portions 44disposed on the wall 21 of the cabinet at the outer sides of theportions 24 and 25 of the slot. Also, it will be noted that the portion43 of these frame members is disposed against the top wall of thecabinet between the arms of the slot. To the inner surface of the topwall 21 of the cabinet there is secured a base member 45 including fourangle iron sections comprising an inner pair of sections 46 and an outerpair 47, the inner sections being bolted to the cross piece 43 of theframe members 34 through 37 while the outer pair are bolted to the footpieces 44 of said members, the said angle iron sections being so spacedapart as to assist in dening the slot through the wall 21 of thecabinet. The outer ends of the angle iron sections of the base member 45are connected with the ends of corresponding sections of a base member48. The members 45 and 48 are adjustable relatively and to this end theangle iron sections of the member 47 are provided with elongated slots49 while the sections o1 the member 48 are provided with extensions 50riveted or otherwise secured to them as at 51 and carrying bolts 52operating in the slots 49.

The outer frame member 38 is secured to the base member 48 as by bolts53 and these frame members each include inwardly directed lugs orextensions 54 and 55 against the inner ends of which are secured trackmembers 56 and 57 as by means of bolts 58. These track members 56 and 57are upper and lower track members and are spaced slightly apart as shownand the track members are formed in sections 59 and 60 each sectioncomprising a substa1tially- U-shaped piece. Section 59 of the trackextends from a point near the end wall 20 of the cabinet to the framemember 37 and has its free end portions bolted to said frame as abovedescribed. Connecting members 61 and 62 are disposed between the frames38 and 37 and connected with them and these members are provided withelongated slots 63 in which operate bolts 64 mounting the track section60 on the machine. Owing to this particular connection and owing to theconnection between the base members it will be obvious that the tracksection 60 may be moved in a direction endwise of the track section 59or toward the left as viewed in Fig. 1. The purpose of this adjustmentwill later be set forth.

At their opposite ends the base members 45 and 48 support bearing blocks65 in which are mounted the lwwer end portions of vertical shafts 66 and67, The upper end portions of these shafts are mounted in bearing blocks68 and 69 the bearing block 68 being supported between angle members 70bolted to the cross bars 41 of the frame members 34 and 35 as at 72. Thebearing block 69 is supported by angle bars 73 secured to the cross bars41 of the frame members 37 and 38. From Fig. 3 it will be seen that theangle bars 73 are provided with elongated slots 74 and that bolts 75passing through said slots adjustably connect the angle bars to theframe member whereby the bearing 69 may be shifted outwardly to providethe adjustment above referred to.

Sprocket wheels 76 and 77 are mounted on the shafts 66 and 67respectively and trained over these sprocket wheels is an endless chainconveyor 78. A trolley means is connected with this chain conveyor andthe trolley means operates on and is guided by the tracks 56 and 57 andthe trolley means serves to support the conveyor particularly when thelatter is carrying a load. While a plurality of these trolley means maybe employed and are shown they are identical in construction and adetailed description of one will, it is believed, suice for all. Eachtrolley means comprises a pair of upright arms 79 each at its upper endequipped with a flanged roller 80 operating on the lower track 57 andguided by the upper track 56 as clearly shown in Figs. 6 and 1l. A block81 is connected with the lower end portion of each arm 79 as by a bolt82 and the lower end portions of these blocks are connected withextensions 83 provided on certain of the links 84 of the conveyor chain.(See Figs. 6, 9 and 11.)

These extensions 83 may be received in slots in the lower edges of theblocks 81 as shown in Fig. 6 and then secured in place as by screws 85.The blocks 81 of the trolley means are connected together by links 86and 87 the outer ends of said links being secured to the blocks as bythe bolts 82 and the inner or adjacent ends of the links being arrangedin overlapping reation and pivotally connected as by a bolt 88. Link 87carries a lug 89 while the link 86 carries a lug 90 and these lugscooperate to prevent pivotal movement of the links about the bolt 88 ina direction inwardly of the conveyor. However, these lugs do permit ofoutward movement of the links as shown in Fig. 13 and this movement isnecessary to permit the trolley means to pass about the sprocket wheels.In actual use the sprocket wheels are relatively small being only ofabout three inches radius and consequently there is a relatively sharpturn at each sprocket wheel.

Any desired means may be provided for operating the conveyor 78 and ashere shown a worm wheel 91 is mounted on the upper end portion of theshaft 66 and meshes with and is driven by akworm 92 on the same-shaftwith a pulley 93, driven as by a belt 94 deriving its power from anysuitable source. It will be understood that that portion of the tracksover the cabinet and that portion of the conveyor likewise over thecabinet follows the slot including the arms 24 and 25. The conveyor issuspended from the track by the trolley means and the two flights orsides of the conveyor while not necessarily in exact alignment with thetracks are in substantial,

alignment with the slot.

I'he conveyor is adapted to carry into and out of the cabinet means tobe cleaned by the sand blast 33. To this end one of the links 84 of theconveyor at each trolley means, or morel oftenif desired, has secured toit a tapered sock'et member 95. This socket member may be welded to thelink as at 96 (see Fig. 7) and the socket member is so' disposed as tobe slightly laterally of the conveyor. For the purpose of connecting thesocket member with the links of the conveyor the said links may beprovided with downwardly extending projections 97 entering into the rearportion of the socket (see Fig. 8) andC welded or otherwise secured inplace. Socket 95 is tapered as shown to receive a correspondinglytapered portion of a quickly detachable supporting member as willappear.

The quick detachable supporting member employed is shown alone in Figs.4 and 5, andthis member, generally designated 98, includes a relativelyfragile cast iron stem or shank 99 formed at iis upper end with atapered head or enlargement 100 adapted to be removably received in thetapered socket 95 above referred to. To remove it from the carrier orsocket 95 all that is necessary is to lift the member 99 upwardly andthen remove it forwardly through the open front wall or slot 95a of thesocket 95. A new carrier may be as ,easily and quickly mounted in thissocket by merely reversing these operations. At its lower end the shank99 carries a series of hooks 101', the said hooks being suitably bent upfrom wire or the like and then disposed partly in i he mold whereby whenthe shank 99 is cast the hooks will be secured in it by casting them inthe lower head 99a of the bar 99. Obviously, the hooks 101 are adaptedto have the articles to be cleaned at'ached to them and as shown in Fig.1 the hooks of each shank 99 are carrying a gate 102 comprising a sandcasting of a number of shear blades. If one of these supports shouldcatch on anything while moving the cast iron shank 99 will merely breakin two and no damage will result to any of the rest of the machine. Anew carrier can be easily and quickly substituted for the broken one asdescribed.

In its end wall 19 the cabinet 15 is provided with an entrance, andinwardly of said entrance there is. arranged a partition 103 which maybe oi.' sheet meal and in this partition there is arranged a door 104comprising a sheet of rubber provided with spaced longitudinally orvertically extending slits 105 and a series of transverse slits leadinginto these longitudinal slits and providing a series of flexible lingers106 at each side of the longitudinal slits 105. This door 104 and theentrance opening in the wall 19 are disposed in alignment and arearranged below and in alignment with the slot in the wall 21 of thecabinet. A similar door or closure with these flexible resilient rubberlingers is provided in the end wall 19. It will be evident that as theVcarrier 98 and the article carried thereby passes through theseclosures the individual ilexible rubber fingers can yield independentlyof each other and therefore as the article goes through the opening thisopening conforms substantially 1o the outline of the article so thatoutward passage o! .sand through the opening is reduced to a minimum.

Assuming that the machine is operating and that articles as the gates102 are to be cleaned the said articles'are hooked onto the hookportions l0l of the supports 98 attached to the conveyor as aboveexplained and the conveyor will then carry these articles through ihesand blast 33. The articles will be carried through the sand blast insuch a manner that first one side of the articles and then the otherwill be presented io be directly acted upon by the sand blast. This isaccomplished since the Shanks 99 of the supports 99 operate through thesubstantially U- shaped slot formed in the upper wall of the cabinet asabove described. In Fig. 2 it will be seen that the shank of one supportis in the arm 25 of the slot while the shank of a second support is inthe arm 24.0f the slot.

Assuming that the arrangement is such that the support enters thecabinet through the arm 25 of the slot then it will be seen that theside A of one ga'e 102 is being directly acted upon bythe sand blast 33while the side B oi' the other gate is also being directly acted upon.Since the conveyor is endless when oit goes about the sprocket '76 thesupports are turned about and therefore one side of a load or article tobe cleaned is presented to the sand blast during movement of the supportdown one arm of the slot and the other side of load or article ispresented during return movement of the support or during movemen*I ofthe support down the other arm of the slot and on its way out of thecabinet. Therefore both sides are acted upon in the same manner by theair blast giving uniform cleaning. Guide bars 107 may be provided toprevent movement of, the articles being cleaned in a direction away fromthe sand blastJ or to prevent a swinging movement of these articlesunder the impact of the sand blast whereby the articles traveling alongone path may not become entangled with vthose traveling along iheopposite path.

Attention is directed to the fact that sand impinging on the baillewhich preferably has a rubber sheet 29 is deected by this sheet assuggested in Fig. 2, and from this figure it will be noted that whileone side of each oad is being directly engaged by the sand blast theopposite side thereof is being engaged by the sand deflected by thebaille or rubber sheet. That is, the side A of the load or articlecarried by the support in the slot 25 is being directly engaged by thesand blast while the side B of said load is bein engaged by thedeflected sand. Likewise, whi e the side B of the load carried by thesupport in the slot 24 is being directly engaged by the sand blast theside A of said load is being engaged by the deflected sand. From this itwill be appreciated that during its movement through a defined path inthe cabinet a casting or other article carried by a supper 1 98 will bethoroughly and uniformly cleaned as both sides are acted upon by boththe direct blast and the indirect or reflected blast.

A door similar to the door 104 may be arranged in the entrance throughthe end wall 19 of the cabinet and it will be noted that theconstruction of this door is such that as diierent parts of the supportand its load pass through the door the fingers 106 which are notdirectly engaged do not move out of place so that at all times there isa minimum of opening through the door whereby the escape of dust intothe atmosphere about the machine is eliminated or minimized. As afurther means for preventing the escape of dust from the cabinet spongerubber strips 108 are secured to the upper surface of the top wall 21 ofthe cabinet in position to have their adjacent edge portions abut overthe slot through which the Shanks 99 of the supports travel. The freeends o1' these strips may normally abut as at 109 whereby the slot issealed. As a support is carried along its shank simply presses aside theadjacent portions of the sponge rubber strips whereby the slot is openedonly as the support progresses through it.

In addition to assisting in deecting the sand as above described therubber sheet 29 also serves to protect or preserve the sand. When a hardsteel plate is substituted for this sheet the sand is dulled or losesits sharpness by contact with the plate and thereby loses its efficiencyfor use in sand blast equipment. The sand does not lose its sharpnessdue to engagement with the rubber sheet 29. As the force of the sand isspent it descends through the cabinet preferably passing through ascreen 110 and on leaving the lower open end 23 of the cabinet passesinto a sand cleaning apparatus generally designated 111 and shown inFig. 14.

However, before the sand leaves the cabinet 15 a considerable portion ofthe dust is removed from the sand such dust' to a large extentrepresenting material removed from the articles being cleaned. For thispurpose a suitable suction apparatus including a pipe or conduit 112 isused to create asuction in the chamber 113 whereby dust will be drawnthrough saidchamber. This chamber is, of course, formed by the plate 26acting as a partition or dividing means and the chamber is incommunication with that portion of the cabinet where the cleaningoperation' takes place since the chambers communicate at the lower edgeof the plate 26. As above suggested the suction is set up in the chamber113 is so regulated whereby no sand will be removed the suction beingsuiicient only to remove ne dustparticles.

0n leaving the open end 22 of the cabinet 15 the used sand passes into areceptacle 114 in which are disposed a series of baiiles 115. The sandentering this receptacle 114 passes from one baille to the next andfinally through a funnel like portion 116 and a, nozzle 117 is deliveredto a receptacle or container 118 from which it may be taken to be againused in the sand blast apparatus. The receptacle 114 is supported as' bymeans of uprights 119 which uprightsalso support a platform 120 onwhichis mounted a suitable suction means or, fan 121 communicating with theinterior of the receptacle 114 so as to remove dust, dirt or the likefrom the sand as it drops from one baille to the next. This fanorexhaust means 121 may deliver into a conduit or stack 122 adapted toremove any collected or extracted dust or dirt-from the vicinity of themachine. n

From the foregoing description it will be seen that the present machineoperates continuously and that it is therefore capable of taking care ofa large amount of work. Further, it will be noted that the actual sandblast operation is enclosed whereby dust does not escape into theatmosphere about the machine and it will further be noted that thesupports 98 are loaded and unloaded at one end of the machine.Therefore, one man may operate the machine doing both the loading andunloading or if the machine is being run at relatively high speed oneoperator may be positioned to unload the supports as they emerge fromthe cabinet while a second operator at the opposite side of the conveyormay load the supports.`

' Since each support includes a plurality of hoops 101 it will beobvious that no great care is required toattach the gates. 102 or otherarticles to the support so as to be most effectively exposed to the Sandblast and that the supports mayl therefore be rapidly loaded andunloaded. In the machine the articles to be cleaned do not come intocontact with one another and the possibilities of the articles beingbroken are reduced to a Heretofore, cast shear blades have been cleanedin tumbling barrels and this operation resulted in considerablebreakage. With the present machine the cleaning operation does notentail breakage. The Shanks 99 of the supports being rather fragilecastings as above explained are adapted to snap should any part becomeclogged or bound. This will result in the work and the hook portion onthe particular support being dropped whereby breakage of the machinewill be prevented. Should one of the supports have its shank portion 99broken as suggested the head 100 of such support will remain in itssocket 95 and may be removed therefrom when such socket emerges from themachine. To accomplish this removal it is but necessary that theoperator shift said head upwardly as suggested by the broken lines inFig. 7.

Having thus set forth the nature of my invention, what I claim is:

1. In a sand blasting machine, a cabinet, a conveyor extending abovesaid cabinet, means for driving said conveyor, supporting meanssuspended from the conveyor and adapted to be carried into and out ofthe cabinet thereby, said supporting means adapted to have articles tobe cleaned attached to it, means for directing a sand blast againstarticles carried by said supporting means while such articles are in thecabinet, and said conveyor arranged to carry said supporting means andarticle into the cabinet along one path and out of the cabinet along asubstantially parallel path whereby on both its inward and outwardmovements the article is presented to the same sand blast.

2. In a sand blasting machine, a cabinet, an endless conveyor at theouter side of said cabinet, means for driving said conveyor, supportingmeans extending from the conveyor and adapted to be carried thereby intoand out of the cabinet, said supporting means adapted to have articlesto be cleaned attached to it whereby said 110 articles will be carriedinto and out'of the cabinet, means for directing a sand blast againstarticles carried by said supporting means while such articles are in thecabinet, and said conveyor arranged to carry said supporting means 115and article to be cleaned into the cabinet along one path and out of thecabinet along a substantially parallel path whereby on both its inwardand outward movements the article is presented to the vsame sand blast.

3. In a sand blasting machine, a cabinet, said cabinet having a U-shapedslot through its upper wall, an endless conveyor extending above saidcabinet, said conveyor having a loading and unloading portion beyond oneend of the cabinet, said slot having its arms opening through said endof the cabinet, said cabinet having an entrance opening through saidend, means for driving the conveyor, supporting means suspended from theconveyor and operating through said 130 entrance and slot whereby it iscarried into and out of the cabinet along a U-shaped path by theconveyor so that its path of outward movement is substantially parallelwith its path of inward movement, said supporting means adapted to 135have articles to be cleaned attached to it, and means directing a sandblast from one side of the cabinet against articles carried by saidsupporting means while such articles are in the cabin'et whereby on bothits inward and outward 140 movements the article is presented to thesame sand blast.l

4. In a sand blasting machine a cabinet, said cabinet having a slotthrough its upper wall, an endless conveyor extending above saidcabinet, 145 said conveyor having a loading and unloading portion beyondone end of the cabinet, said slot opening through said end of thecabinet, said cabinet having an entrance through said end,

A' io means directing a sand blast against articles carried by saidsupporting means while such articles are in the cabinet. u

5. In a sand blasting machine, a cabinet, a deector plate within thecabinet, means directing a sand blast from one' side of the cabinettoward said deflector plate, means for carrying an article to be cleanedinto and out of the cabinet between the deflector plate and the saidside of the cabinet, and said means including means whereby the articlewill have one side presented to the sand blast duringits movement intothe cabinet and its other side presented to the same sand blast duringits movement out of the cabinet.

6. In a sand blasting machine, a cabinet, a deflector plate within thecabinet, means direct- `ing a sand blast i'rom` one side @of the cabinettoward the inner side of said deflector plate, a sheet oi rubber on theinner surface uof said plate and against which the sand blast mayimpinge and be deflected, means for carrying an article to be cleanedinto and out of the cabinet through said sand blast, and said meansadapted to position said article so that one of its sides will bedirectly engaged by the sand blast while its other side will be vengagedby sand deected by said rubber sheet. y

'7. In a sand blasting machine. a cabinet, a deiiector plate within thecabinet, means directing a sand blast from one side of said cabinettoward the inner side of the deilector plate, a sheet of rubber on theinner surface of the deiiector plate and against which the sand blastmay impinge and be deflected, means for carrying an article to becleaned into and out of the cabinet through said sand blast, and saidmeans including means whereby the article will first have one of itssides directly engaged by the sand blast while its other side will besimultaneously engaged by sand'deilected by the rubber sheet and willthen have its said other side directly engaged by the'sand blast whileits first side is engaged by sand deflected by the rubber sheet.

8. In a sand blasting machine, a cabinet, a deilector plate within thecabinet, means directing a sand blast from one side of the cabinettoward said defiector plate, means for carrying an article to be cleanedinto and out of the cabinet between the deflector plate and the saidside of the cabinet, said means including means whereby the said articlewill have first one side and then another presented to the said blast,and

guide means within the cabinet and positioned to be engaged by thearticle to be cleaned to prevent movement of the article in a directionaway from the sand blast.

9. In a sand blasting machine, a cabinet, track means extending abovethe cabinet, an endless' conveyor above the cabinet and below said trackmeans, means `for driving they conveyor, trolley means on the track andconnected with the conveyor to support thesame, supporting meansconnected with the' conveyor below said 1 trolley means and adapted tobe moved into and out of the cabinet by the conveyor, said supportingmeans adapted to have articles to be cleaned atto be cleaned arepresented to the same sand blast on both their movements into and out ofthe cabinet.

10. In a sand blasting machine, a cabinet, an endless conveyor abovesaidcabinet, a pair of spaced sprocket wheels over which said conveyoris trained, track means above the conveyor, trolley means on the trackand connected with and Y supporting the conveyor, said trolley meanscomprising a pair of members each connected at one end #with theconveyor and each at its opposite end carrying a wheel operating on thetrack means, a pair of links pivoted to said members and to each other,cooperating lugs on said links whereby they may move relatively in onedirection only about their pivotal connection, supporting meansconnected with the conveyor below said trolley meansand adapted to bemoved into and out of the cabinet by the conveyor, said supporting meansadapted to have articles to be cleaned attached to it, and means fordirecting a sand blast against articles carried by said supporting meanswhile such articles are in theV cabinet.

11. In a sand blasting machine, a cabinet, a conveyor extending abovesaid cabinet, means for driving said conveyor, supporting meanssuspended from the conveyor and adapted to be carried into and out ofthe cabinet thereby, said supporting means `comprising a relativelyfragile shank carrying hooks at its lower end and at its upper endremovably connected with the conveyor, said supporting means adapted tocarry articles disposed on its hook into and out of the cabinet, saidshank adapted to break and permit said hooks to drop with the articlesbeing cleaned when such articles become caught while passing through thecabinet, and means for directing a sand blast against articles carriedby said supporting means While such articles are in the cabinet.

12. In a sand blasting machine, a cabinet, an endless chain conveyorabove said cabinet, a pair of spaced sprocket wheels over which saidconveyer is trained, track means above the conveyor, said track meanscomprising a pair of sections, a frame means supporting each of saidsections, each of said frame means mounting one of said sprocket wheels,trolley means on the track and connected with and supporting theconveyor, supporting means connected with the conveyor and adapted to bemoved into and out of the cabinet thereby, said supporting means adaptedto yhave articles to be cleaned attached to it, means for directing asand blast against articles carried by the supporting means While sucharticles are in the cabinet, and means adjustably connecting said tracksections whereby one track section and its sprocket wheel may beadjusted in a direction away from the other thereof to tension theconveyor.

13. In a sand blasting machine, a cabinet. means directing a sand blastacross the cabinet from one sidethereoi, and means for carrying anarticle to bev cleaned into and through the sand blast with one sideexposed thereto and for then reversing the article and carrying it back.through the same sand blast with the opposit side of the article exposedto the blast.

14. In a sand blasting machine, a cabinet, means directinga sand blastacross the cabinet outside of and associated with said cabinet,supporting means moved by said continuously moving means and includingportions adapted to be moved into and out of the cabinet, saidsupporting means adapted to have an article to be cleaned removablyattached thereto-whereby such article will be carried into and out ofthe cabinet through said sand blast, and said continuously moving meansarranged to carry said supporting means and article into the cabinetalong one path with one side of the article presented to the sand blastand out of the cabinet along a substantially parallel path with theother side of the article presented to the same sand blast.

16. In a sand blasting machine, a cabinet, means for directing a sandblast across the cabinet, means for carrying an article to be cleanedinto and out of the cabinet through said said blast, said means carryingthe article into the cabinet along one path and out of the cabinet alonga substantiallyparallel path whereby the article to be cleaned ispresented to the same sand blast on both its m vements into and out ofthe cabinet, and said ar icle carrying means including means whereby thearticle will have one side presented to the sand blast during movementof the article into the cabinet and its other side presented to the sandblast during movement out of the cabinet.

17. In a sand blasting machine, a cabinet. a

`along one path andr out of the cabinet along a substantially parallelpath whereby on bothl its inward and outward movements the article ispresented to the same sand blast, and said conveyor including meanswhereby the article has one side presented to the sand blast on inwardmovement of the article and another side presented to the sand blast onoutward movement of the article.

' PERCIVAL H. BEST.

